Infants born with spina bifida (SB) represent a population with significant sensorimotor disruptions at the level of the spinal cord, high potential for capitalizing on the plasticity available in the young neuromotor system, yet a serious void exists in scientific and therapeutic efforts to examine, assess, and maximize this potential. Adults who experience spinal cord injuries are engaged within weeks in intensive therapeutic protocols, such as body weight supported treadmill therapy (BWSTT). Infants with SB, whose lesions occur in the first month of gestation, typically wait until they are 6-9-months old for mild physical therapy efforts to begin. We believe the primary reason interventions have been so limited is that empirical evidence is lacking. The overarching goal of this proposal is to create an extensive and thorough foundation of basic information about the intrinsic sensorimotor capacities of infants with SBacross the first year of postnatal life and their responsiveness to various forms of enhanced sensory input. We anticipate these results will become the basis for designing future clinical trials of the impact of specific intervention protocols. Specific Aim 1: map the developmental trajectory of the stepping and non-stepping responses (including kinematic and kinetic data) of babies born with SB to being supported upright on a small motorized treadmill. Specific Aim 2: determine if by enhancing the sensory input to their systemswe can improve the frequency and quality of their motor output when in the treadmill context. Specific Aim 3: assess the integrity of mono- and polysynaptic sensorimotor loop function of locomotor muscles; test the impact of vibration to the soles of the feet and leg muscles on stepping responses when supported upright but not on a treadmill. Subsequently, we will compare different levels of neuromotor lesion with responsiveness to various modes of sensory enhancement. In sum, we believe these data will provide knowledge of the sensorimotor capacities of the legs of infants born with SB over the first postnatal year, including their responses to various forms of enhanced sensory stimulation, from visual flow to direct tissue vibration. The results will inform scientists and medical professionals about the potential these infants possess and techniques that might be used to promote optimal locomotor development for infants born with SB.